System-Generated Electromagnetic Pulse and Spacecraft Charging Effects: A Review of the Technology as Applied to System Hardening Problems

Investigations of several phenomenological issues remain to be completed. Specifically, for SCC there are the issues of discharge and blowoff from dielectric surfaces, and discharge within PC boards. These subjects are being studied intensely; miscellaneous other issues are also being addressed. At present, SGEMP and SCC phenomena are sufficiently well understood to allow high confidence conservative hardened system designs. These are designs which ulitize extra quantities of rf shielding and other protection techniques to accommodate lack of full understanding of some phenomenological and system coupling/response details. In this regard, additional work is needed in the area of environment/response parameter tradeoff studies to identify hardened system designs that are optomized for minimal weight. Full-scale tests of complex systems very often produce surprise results which reveal flaws in engineering designs or errors in implementation of adequate designs. Closer coordination between hardening technologists and system designers is needed in the future to help minimize such errors. More work is needed on selected hardness assurance and hardness maintainence (HA/HM) issues. It must be determined to what degree the requirement exists that box-level current injection testing for HA/HM be carried out with simultaneous ionizing radiation. In general, greater efforts should be expended in the future to integrate HA/HM testing considerations into system designs. Future trends toward more complex and sophisticated systems will require increasing care in development and implementation of hardened system designs.